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Answer
By Wilson's theorem, 72! mod 73 = 72
72 mod 73 = -1
71 mod 73 = -2 and so on
So, 72! mod 73 = $$36!^2$$ mod 73 = 72
=> $$t^2$$ mod 73 = 72
=> $$t^2$$ + 1 = 73k
This satisfied for t = 27
So, 27 is the remainder of 36! mod 73
